Marijuana

76. Cannabinoid Withdrawal

"The withdrawal syndrome associated with dronabinol, the API [Active Pharmaceutical Ingredient] in Marinol®, produces symptoms in humans such as restlessness, irritability, mild agitation, anxiety, anger, insomnia, sleep EEG disturbances, nausea, decreased appetite, and decreased weight. Since a withdrawal syndrome is indicative of physical dependence, it is reasonable to conclude that generic dronabinol products (both naturally-derived [from the cannabis plant] or synthetically produced, and in hard or soft gelatin capsules) in sesame oil, will also produce physical dependence similar to those produced by Marinol®."

Federal Register, "Listing of Approved Drug Products Containing Dronabinol in Schedule III," Vol. 75, No. 210, Monday, November 1, 2010, pp. 67054 to 67059.
http://www.gpo.gov...
===
"MARINOL® (dronabinol) Capsules," (Abbott Laboratories: Abbott Park, IL, July 2006), pp. 11.
http://www.accessdata.fda.gov...

77. Marijuana Use as a Gateway to Other Drug Use

"There is no conclusive evidence that the drug effects of marijuana are causally linked to the subsequent abuse of other illicit drugs."

Janet E. Joy, Stanley J. Watson, Jr., and John A Benson, Jr., "Marijuana and Medicine: Assessing the Science Base," Division of Neuroscience and Behavioral Research, Institute of Medicine (Washington, DC: National Academy Press, 1999), p. 6.
http://books.nap.edu...

78. Patterns in Progression of Drug Use Over Time

"Patterns in progression of drug use from adolescence to adulthood are strikingly regular. Because it is the most widely used illicit drug, marijuana is predictably the first illicit drug most people encounter. Not surprisingly, most users of other illicit drugs have used marijuana first. In fact, most drug users begin with alcohol and nicotine before marijuana, usually before they are of legal age."

Janet E. Joy, Stanley J. Watson, Jr., and John A Benson, Jr., "Marijuana and Medicine: Assessing the Science Base," Division of Neuroscience and Behavioral Research, Institute of Medicine (Washington, DC: National Academy Press, 1999), p. 99.
http://books.nap.edu...

79. Effect of Marijuana Use by Adolescents on Cognition and IQ Development

"In line with previous work, we found that cannabis users had lower teenage IQ scores and poorer educational performance than teenagers who had never used cannabis. At the same time, cannabis users also had higher rates of childhood behavioural problems, childhood depressive symptoms, other substance use (including use of cigarettes and alcohol) and maternal use of cannabis during pregnancy. After adjustment to account for these group differences, cannabis use by the age of 15 did not predict either lower teenage IQ scores or poorer educational performance. These findings therefore suggest that cannabis use at the modest levels used by this sample of teenagers is not by itself causally related to cognitive impairment. Instead, our findings imply that previously reported associations between adolescent cannabis use and poorer intellectual and educational outcomes may be confounded to a significant degree by related factors."

C Mokrysz, R Landy, SH Gage, MR Munafò, JP Roiser, and HV Curran, "Are IQ and educational outcomes in teenagers related to their cannabis use? A prospective cohort study," Journal of Psychopharmacology, 0269881115622241, first published on January 6, 2016 doi:10.1177/0269881115622241
http://jop.sagepub.com...
http://jop.sagepub.com...

80. Effect of Marijuana Use by Adolescents on Cognition and IQ

"In summary, the notion that cannabis use itself is causally related to lower IQ and poorer educational performance was not supported in this large teenage sample. However, this study indeed has limitations, in particular the young age of outcome assessment. While we have demonstrated that confounding may be an explanation for links between cannabis use and poorer outcomes, large prospective cohorts tracking young people prior to, during and after stopping cannabis use, using more objective measures of drug use (e.g. the new NIH-funded ‘ABCD study’ in the United States; National Institute on Drug Abuse, 2015) are required before we can make strong conclusions. Cigarette smoking in particular has once again (Hooper et al., 2014; McCaffrey et al., 2010; Silins et al., 2014; Stiby et al., 2014) been highlighted as an important factor in adolescent outcomes, as well as a robust independent predictor of educational performance, and the reasons for this need to be elucidated."

C Mokrysz, R Landy, SH Gage, MR Munafò, JP Roiser, and HV Curran, "Are IQ and educational outcomes in teenagers related to their cannabis use? A prospective cohort study," Journal of Psychopharmacology, 0269881115622241, first published on January 6, 2016 doi:10.1177/0269881115622241
http://jop.sagepub.com...
http://jop.sagepub.com...

81. Effect of Cannabis Use and Nicotine Use by Adolescents on Cognition and IQ

"Compared with those in our sample who had never tried cannabis, teenagers who had used cannabis at least 50 times were 17 times more likely (84% vs. 5%) to have smoked cigarettes more than 20 times in their lifetime. Accounting for group differences in cigarette smoking dramatically attenuated the associations between cannabis use and both IQ and educational performance. Further, even after excluding those who had never tried cannabis, cigarette users were found to have lower educational performance (adjusted performance 2.9 percentage points lower, approximately equivalent to dropping two grades on one subject taken at GCSE) relative to those who had never tried cigarettes. A relationship between cigarette use and poorer cognitive (Chamberlain et al., 2012; Hooper et al., 2014; Weiser et al., 2010; Whalley et al., 2005) and educational (McCaffrey et al., 2010; Silins et al., 2014; Stiby et al., 2014) outcomes has been noted previously, and may have a number of explanations. Cigarette use may have a negative impact on cognitive ability. However, this is not supported by the experimental psychopharmacology literature, which robustly shows that acute nicotine administration results in transient cognitive enhancement (Heishman et al., 2010). Alternatively, reverse causality may contribute to this relationship, for example performing poorly at school may lead to increased engagement in risky behaviours such as cigarette smoking. Further, residual confounding may contribute to this link: cigarette smoking may be a marker of unmeasured factors, for example social adversity during adolescence, that influence both IQ and educational attainment."

C Mokrysz, R Landy, SH Gage, MR Munafò, JP Roiser, and HV Curran, "Are IQ and educational outcomes in teenagers related to their cannabis use? A prospective cohort study," Journal of Psychopharmacology, 0269881115622241, first published on January 6, 2016 doi:10.1177/0269881115622241
http://jop.sagepub.com...
http://jop.sagepub.com...

82. IQ Decline Among Adolescent-Onset Marijuana Users

"In the present study, the most persistent adolescent-onset cannabis users evidenced an average 8-point IQ decline from childhood to adulthood. Quitting, however, may have beneficial effects, preventing additional impairment for adolescent-onset users. Prevention and policy efforts should focus on delivering to the public the message that cannabis use during adolescence can have harmful effects on neuropsychological functioning, delaying the onset of cannabis use at least until adulthood, and encouraging cessation of cannabis use particularly for those who began using cannabis in adolescence."

Madeline H. Meier, Avshalom Caspi, Antony Ambler, HonaLee Harrington, Renate Houts, Richard S. E. Keefe, Kay McDonald, Aimee Ward, Richie Poulton, and Terrie E. Moffitt, "Persistent Cannabis Users Show Neuropsychological Decline from Childhood to Midlife, Proceedings of the National Academy of Sciences, 2012, p. 6.
www.pnas.org...

83. Marijuana Use and IQ

"Although the heavy current users experienced a decrease in IQ score, their scores were still above average at the young adult assessment (mean 105.1). If we had not assessed preteen IQ, these subjects would have appeared to be functioning normally. Only with knowledge of the change in IQ score does the negative impact of current heavy use become apparent."

Fried, Peter, Barbara Watkinson, Deborah James, and Robert Gray, "Current and former marijuana use: preliminary findings of a longitudinal study of effects on IQ in young adults," Canadian Medical Association Journal, April 2, 2002, 166(7), p. 890.
http://www.ncbi.nlm.nih.gov...

84. Cannabis and Cognition

"The results of our meta-analytic study failed to reveal a substantial, systematic effect of long-term, regular cannabis consumption on the neurocognitive functioning of users who were not acutely intoxicated. For six of the eight neurocognitive ability areas that were surveyed. the confidence intervals for the average effect sizes across studies overlapped zero in each instance, indicating that the effect size could not be distinguished from zero. The two exceptions were in the domains of learning and forgetting."

Grant, Igor, et al., "Non-Acute (Residual) Neurocognitive Effects Of Cannabis Use: A Meta-Analytic Study," Journal of the International Neuropsychological Society (Cambridge University Press: July 2003), 9, p. 685.
http://www.csdp.org...

85. Cognitive Deficit Among Adolescent-Onset Marijuana Users

"Our findings suggest that regular cannabis use before age 18 y predicts impairment, but others have found effects only for younger ages (10, 15). Given that the brain undergoes dynamic changes from the onset of puberty through early adulthood (37, 38), this developmental period should be the focus of future research on the age(s) at which harm occurs."

Madeline H. Meier, Avshalom Caspi, Antony Ambler, HonaLee Harrington, Renate Houts, Richard S. E. Keefe, Kay McDonald, Aimee Ward, Richie Poulton, and Terrie E. Moffitt, "Persistent Cannabis Users Show Neuropsychological Decline from Childhood to Midlife, Proceedings of the National Academy of Sciences, 2012, p. 1.
http://www.pnas.org...

86. Marijuana Use and Cognition

"In conclusion, our meta-analysis of studies that have attempted to address the question of longer term neurocognitive disturbance in moderate and heavy cannabis users has failed to demonstrate a substantial, systematic, and detrimental effect of cannabis use on neuropsychological performance. It was surprising to find such few and small effects given that most of the potential biases inherent in our analyses actually increased the likelihood of finding a cannabis effect."

Grant, Igor, et al., "Non-Acute (Residual) Neurocognitive Effects Of Cannabis Use: A Meta-Analytic Study," Journal of the International Neuropsychological Society (Cambridge University Press: July 2003), 9, p. 687.
http://www.csdp.org...

87. Medical Marijuana - Research - 12-20-09

"Nevertheless, when considering all 15 studies (i.e., those that met both strict and more relaxed criteria) we only noted that regular cannabis users performed worse on memory tests, but that the magnitude of the effect was very small. The small magnitude of effect sizes from observations of chronic users of cannabis suggests that cannabis compounds, if found to have therapeutic value, should have a good margin of safety from a neurocognitive standpoint under the more limited conditions of exposure that would likely obtain in a medical setting."

Grant, Igor, et al., "Non-Acute (Residual) Neurocognitive Effects Of Cannabis Use: A Meta-Analytic Study," Journal of the International Neuropsychological Society (Cambridge University Press: July 2003), 9, pp. 687-8.
http://www.csdp.org...

88. Marijuana Use and Cognition

"Current marijuana use had a negative effect on global IQ score only in subjects who smoked 5 or more joints per week. A negative effect was not observed among subjects who had previously been heavy users but were no longer using the substance. We conclude that marijuana does not have a long-term negative impact on global intelligence. Whether the absence of a residual marijuana effect would also be evident in more specific cognitive domains such as memory and attention remains to be ascertained."

Fried, Peter, Barbara Watkinson, Deborah James, and Robert Gray, "Current and former marijuana use: preliminary findings of a longitudinal study of effects on IQ in young adults," Canadian Medical Association Journal, April 2, 2002, 166(7), p. 887.
http://www.ncbi.nlm.nih.gov...

89. Marijuana Use and Cognition

"Other studies have found short term residual effects of cannabis use on memory and cognition (34, 35) that are more severe among women (36) and heavy users (37). However, our data suggest that over the long term cannabis use is not associated with greater declines in cognition among men, women, or heavy users. The study design we used included several of the features proposed by Pope et al. (34) as critical to addressing the long term effects of cannabis on cognition: naturalistic follow-up, a large sample size, a population basis, comparison of light cannabis use with heavy use, and the construction of models accounting for the effects of gender and use of illicit drugs, alcohol, and tobacco. Therefore, these results would seem to provide strong evidence of the absence of a long term residual effect of cannabis use on cognition."

Constantine G. Lyketsos, Elizabeth Garrett, Kung-Yee Liang, and James C. Anthony. (1999). "Cannabis Use and Cognitive Decline in Persons under 65 Years of Age," American Journal of Epidemiology, Vol. 149, No. 9.
http://aje.oxfordjournals.org/...

90. Marijuana Use and Memory

"These results can be interpreted in several ways. A statistically reliable negative effect was observed in the domain of learning and forgetting, suggesting that chronic long-term cannabis use results in a selective memory defect. While the results are compatible with this conclusion, the effect size for both domains was of a very small magnitude. The "real life" impact of such a small and selective effect is questionable. In addition, it is important to note that most users across studies had histories of heavy longterm cannabis consumption. Therefore, these findings are not likely to generalize to more limited administration of cannabis compounds, as would be seen in a medical setting."

Grant, Igor, et al., "Non-Acute (Residual) Neurocognitive Effects Of Cannabis Use: A Meta-Analytic Study," Journal of the International Neuropsychological Society (Cambridge University Press: July 2003), 9, p. 686.
http://www.csdp.org...

91. Psychological Effects of Cannabis Compared With Exercise

"The [endo] cannabinoids produce psychological states that closely parallel several experiences described as being related to the runner’s high. Compared with the opioid analgesics, the analgesia produced by the endocannabinoid system is more consistent with exercise induced analgesia. Activation of the endocannabinoid system also produces sedation, anxiolysis, a sense of wellbeing, reduced attentional capacity, impaired working memory ability, and difficulty in time estimation. This behavioural profile is similar to the psychological experiences reported by long distance runners."

Dietrich, A and McDaniel, W, "Endocannabinoids and exercise," British Journal of Sports Medicine (Middlesex, United Kingdom: British Association of Sport and Exercise Medicine, October 2004), Volume 38, pp. 539-540.
http://www.ncbi.nlm.nih.gov/pm...

92. Marijuana Use and "Amotivational Syndrome"

"One of the major concerns about the psychological effects of chronic heavy cannabis use has been that it impairs adult motivation. The evidence for an 'amotivational syndrome' among adults consists largely of case histories and observational reports (e.g. Kolansky and Moore, 1971; Millman and Sbriglio, 1986). The small number of controlled field and laboratory studies have not found compelling evidence for such a syndrome (Dornbush, 1974; Negrete, 1983; Hollister, 1986). The evidential value of the field studies is limited by their small sample sizes, and the limited sociodemographic characteristics of their samples, while the evidential value of the laboratory studies is limited by the short periods of drug use, the youthful good health of the volunteers, and minimal demands made on volunteers in the laboratory (Cohen, 1982). Some regular cannabis users report a loss of ambition and impaired school and occupational performance as adverse effects of their use (e.g. Hendin et al, 1987) and that some ex-cannabis users give impaired occupational performance as a reason for stopping (Jones, 1984). Nonetheless, it is doubtful that cannabis use produces a well defined amotivational syndrome. It may be more parsimonious to regard the symptoms of impaired motivation as symptoms of chronic cannabis intoxication rather than inventing a new psychiatric syndrome."

Hall, W., Room, R. & Bondy, S., WHO Project on Health Implications of Cannabis Use: A Comparative Appraisal of the Health and Psychological Consequences of Alcohol, Cannabis, Nicotine and Opiate Use, August 28, 1995 (Geneva, Switzerland: World Health Organization, March 1998).
http://www.druglibrary.net...

93. Cannabis and Psychotic Experiences

"This 10 year follow-up study showed that incident cannabis use significantly increased the risk of incident psychotic experiences. The association was independent of age, sex, socioeconomic status, use of other drugs, urban/rural environment, and childhood trauma; additional adjustment for other psychiatric diagnoses similarly did not change the results. There was no evidence for self medication effects as psychotic experiences did not predict later cannabis use. The results thus help to clarify the temporal association between cannabis use and psychotic experiences by systematically addressing the issue of reverse causality, given that the long follow-up period allowed exclusion of all individuals with pre-existing psychotic experiences or pre-existing cannabis use. In addition, cannabis use was confirmed as an environmental risk factor impacting on the risk of persistence of psychotic experiences (fig 3)."

Keupper, Rebecca, van Os, Jim, et al., "Continued Cannabis Use and Risk of Incidence and Persistence of Psychotic Symptoms: 10-Year Follow-Up Cohort Study, British Medical Journal, 2011;342:d738 doi:10.1136/bmj.d738

94. Overall Psychological Safety of Cannabis: Schizophrenia and Psychosis

"A review of the literature suggests that the majority of cannabis users, who use the drug occasionally rather than on a daily basis, will not suffer any lasting physical or mental harm. Conversely, as with other 'recreational' drugs, there will be some who suffer adverse consequences from their use of cannabis. Some individuals who have psychotic thought tendencies might risk precipitating psychotic illness. Those who consume large doses of the drug on a regular basis are likely to have lower educational achievement and lower income, and may suffer physical damage to the airways. They also run a significant risk of becoming dependent upon continuing use of the drug. There is little evidence, however, that these adverse effects persist after drug use stops or that any direct cause and effect relationships are involved."

Iversen, Leslie L., PhD, FRS, "Long-Term Effects of Exposure to Cannabis," Current Opinion in Pharmacology, Feb. 2005, Vol. 5, No. 1, p. 71.
http://www.ncbi.nlm.nih.gov...

95. Cannabis and Diagnoses of Schizophrenia and Psychoses

"In terms of the model set out in the Introduction, the expected rise in diagnoses of schizophrenia and psychoses did not occur over a 10 year period. This study does not therefore support the specific causal link between cannabis use and the incidence of psychotic disorders based on the 3 assumptions described in the Introduction. This concurs with other reports indicating that increases in population cannabis use have not been followed by increases in psychotic incidence (Macleod et al., 2006; Arsenault et al., 2004; Rey and Tennant, 2002). However, it is not in line with findings of a rise in first admission rates for psychotic disorders among young people in Zurich following increases in cannabis availability and consumption (Ajdacic-Gross et al., 2007). One factor involved in this discrepancy may be the potency of the cannabis consumed, which varies considerably within Europe (EMCDDA, 2008). In addition, a Netherlands study found that high-potency cannabis obtained from ‘coffee shops’ led to higher levels of tetrahydrocannabinol (THC) in the blood, with young males aged 18–45 at particular risk for excessive consumption (Mensinga et al., 2006)."

Frisher, Martin; Crome, Ilana; Orsolina, Martino; and Croft, Peter, "Assessing the impact of cannabis use on trends in diagnosed schizophrenia in the United Kingdom from 1996 to 2005," Schizophrenia Research (Nashville, Tennessee: Schizophrenia International Research Society, September 2009) Vol. 113, Issue 2, p. 126.
http://www.ukcia.org...

96. Cannabis and Psychosis

"Although individual lifetime risk of chronic psychotic disorders such as schizophrenia, even in people who use cannabis regularly, is likely to be low (less than 3%), cannabis use can be expected to have a substantial effect on psychotic disorders at a population level because exposure to this drug is so common."

Moore, Theresa H M; Zammit, Stanley; Lingford-Hughes, Anne; Barnes, Thomas R E; Jones, Peter B; Burke, Margaret; Lewis, Glyn, "Cannabis use and risk of psychotic or aff ective mental health outcomes: a systematic review," The Lancet (London, United Kingdom: July 28, 2007) Vol 370, p. 327.
http://www.ncbi.nlm.nih.gov...
http://www.thelancet.com...

97. Cannabis and Psychosis

"First, the use of cannabis and rates of psychotic symptoms were related to each other, independently of observed/non-observed fixed covariates and observed time dynamic factors (Table 2). Secondly, the results of structural equation modeling suggest that the direction of causation is that the use of cannabis leads to increases in levels of psychotic symptoms rather than psychotic symptoms increasing the use of cannabis. Indeed, there is a suggestion from the model results that increases in psychotic symptoms may inhibit the use of cannabis."

Fergusson, David M., John Horwood & Elizabeth M. Ridder, "Tests of Causal Linkages Between Cannabis Use and Psychotic Symptoms," Addiction, Vol. 100, No. 3, March 2005, p. 363.
http://www.ncbi.nlm.nih.gov...
http://www.csdp.org...

98. Cannabis and Psychosis

"The lead researcher in the Christchurch study, Professor David Fergusson, said the role of cannabis in psychosis was not sufficient on its own to guide legislation. 'The result suggests heavy use can result in adverse side-effects,' he said. 'That can occur with ( heavy use of ) any substance. It can occur with milk.' Fergusson's research, released this month, concluded that heavy cannabis smokers were 1.5 times more likely to suffer symptoms of psychosis that non-users. The study was the latest in several reports based on a cohort of about 1000 people born in Christchurch over a four-month period in 1977. An effective way to deal with cannabis use would be to incrementally reduce penalties and carefully evaluate its impact, Fergusson said. 'Reduce the penalty, like a parking fine. You could then monitor ( the impact ) after five or six years. If it did not change, you might want to take another step.'

Bleakley, Louise, "NZ Study Used in UK Drug Review," The Press (Christchurch, New Zealand), March 22, 2005.
http://www.mapinc.org...

99. Marijuana Use and Violent Behavior

"Laboratory studies also find no link between THC intoxication and violence. Most people who ingest THC before performing a competitive task in the laboratory do not show more aggression than people who receive placebos; occasionally they show decreased hostility. Numerous scientific panels sponsored by various governments invariably report that marijuana does not lead to violence.(751)"

Carter, Gregory T.; Earleywine, Mitchell; McGill, Jason T., "Exhibit B: Statement of Grounds," Rulemaking petition to reclassify cannabis for medical use from a Schedule I controlled substance to a Schedule II (Office of Lincoln D. Chafee, Governor Rhode Island and Office of Christine O. Gregoire, Governor of Washington: Letter to Michelle Leonhard, Administrator of the Drug Enforcement Administration, November 30, 2011), p. 38.
http://big.assets.huffingtonpost.com...

100. Early Use of Marijuana

"The younger and more often teens use marijuana, the more likely they are to engage in other substance use and the higher their risk of developing a substance use disorder. Among high school students, 7.5 percent used marijuana for the first time before the age of 13. CASA’s analysis of national data finds that the average age of initiation of marijuana use among high school students is 14.3 years old. Compared to those who began using marijuana after age 21, those who first used it before age 15 are:
• More likely to have ever smoked a cigarette (93.3 percent vs. 86.4 percent);
• More than twice as likely to have ever misused controlled prescription drugs (56.5 percent vs. 22.9 percent); and
• Two and a half times as likely to have ever used other illicit drugs (70.2 percent vs. 27.8 percent)."

"Adolescent Substance Abuse: America's #1 Public Health Problem," National Center on Addiction and Substance Abuse at Columbia University, June 2011, p. 27.
http://www.casacolumbia.org...

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